I saw a youtube video of a single mother who job it was to cut out the ice from underneath the ships to create space to do the repairs. Apparently its a very dangerous job because you can easily end up frozen to the river if you're not careful. Must be the same one mentioned in the article.
youtube.com/watch?v=Lu9P3VaMCho
I'm reminded of the worker in this bit - https://www.youtube.com/watch?v=6U3g-h1rxQw
Absolutely loves her job. Screams a little bit every time she swings the pickaxe below a certain depth though. As one does.